WELTEC builds another agricultural biogas plant

WELTEC BIOPOWER, together with German manufacturer Domaix Energie, is setting up a plant with heat source concept in Mirecourt (Lorraine), France. The "Méthavigne" 255-kW biogas project comes with fringe benefits for farmer Nicolas Jacquot and a nearby medical center ("Centre hospitalier Ravenel") of the Département Vosges.
Representatives of the medical center quickly warmed up to the pipeline construction and heat transfer project. "With the exhaust heat from the plant, our institution will be able to cover its entire hot water needs, starting from the commissioning in October 2015," says Hervé Buffe, technical manager of the hospital. The suitability of the location and the short distance of only one kilometer from the biogas CHP plant convinced Buffe and his colleagues of the plant’s advantages. With uninterrupted procurement of green heat, the clinic will save costs and streamline its ecological profile.
When biogas plant operator Jacquot and Martin Nippé, Director of Domaix Energie, contacted the medical center’s representatives, they were aware of the clinic's ecological orientation. Today fulfilment of environmental requirements is a must, and the placement of public orders by the clinic is subject to strict sustainability standards. With their concept, WELTEC and Domaix Energie fulfill these standards. With this in mind Buffe gave his OK: "We were immediately fascinated by the idea ‒ everything was perfect."
In addition to a continually reliable heat supply, the sufficient quantity generated by the biogas plant operation is a big plus. The plant's heat offer is so extensive that it covers the entire hot water supply of the medical center plus the heat needs of the home of the Jacquot family.
For the farmer, the business field "energy" blends in nicely with the overall strategy. The cultivated area of 375 hectares and 850 cattle allow the Jacquot family to produce all the raw materials they need for the energy generation. The 2,226-m³ stainless-steel digester will be fed with a feedstock mix of cattle manure, maize silage, crop dust, straw, grass, fruit pomace, flotation grease and food leftovers in the amount of 28 t/day.
The new 60-m³ BIG-Mix dosing feeder serves as an input system. The benefit is its ability to process long-fiber substrates such as solid manure or grass in an energy-saving manner with the individually driven push strips. A vertical mixing screw then passes on the material to the second input level, the MULTIMix, mashes it with liquid manure and introduces it to the digester. After the fermentation process, a CHP plant transforms the biogas to power, which is fed into the public grid and heat. Moreover, the digestate is stored in a 5,007-m³ stainless-steel tank and can be used on the farmer's own fields as an effective low-odor fertilizer.
These technical details are also relevant for Buffe, as the clinic's continuous supply and economic reliability depends on them. "This partnership between a public hospital and a private farm is probably one of the first of this type in Lorraine or even in all of France. A key aspect for us is that this concept enables us to cut our total gas consumption by 7 percent," he says.